Advanced hydrogel therapeutics for intervertebral disc degeneration: Engineering structural–functional properties in natural and synthetic biomaterials

Low back pain is a global health challenge, imposing substantial socioeconomic burdens. Intervertebral disc degeneration (IVDD) is a leading cause of low back pain and can lead to further spinal complications. Current treatments for IVDD are limited to conservative measures and surgery, lacking curative options. Advances in biomaterials science and regenerative medicine have introduced bioactive hydrogels as promising treatments for IVDD. This review summarizes the physiology of the intervertebral disc, the pathophysiology of IVDD, existing diagnostic methods, and current treatment strategies. Importantly, this review examines recent advances in hydrogel treatments for IVDD, emphasizing the biological and material properties of various hydrogels. It compares the advantages and limitations of natural and synthetic hydrogels, outlining the classification of hydrogel delivery substances. Lastly, it identifies current challenges and suggests future research directions to optimize the application of bioactive materials in IVDD treatment.